Door construction



7, 1957 w. A. TERNES ETAL DOOR CONSTRUCTION 2 Sheets-Sheet 1 Filed Aug. 13, 1956 7, 1957 w. A. TERNES EI'AL 2,804,136

DOOR CONSTRUCTION Filed Aug. 13, 1956 2 Sheets-Sheet 2 m W FE: AL.

INVENTORS E fi. 72??7765 y 77 Z. i272 Z,3@4,l36 Patented Aug. 27, 1957 fine DOGR CQNSTRUCTION William A. Ternes, Grosse Pninte, and Ralph E. Ford, Harper Woods, MiclL; said Ford assignor to said Ternes Application August 13, 1956, Serial No. 603,481

11 Claims. or. 160-199) This invention relates to door constructions and more particularly to folding door constructions having sliding and pivoting sheet metal panels.

A door construction particularly adapted to close wide openings of closets or doorways and which can be opened to expose the complete closet or door opening is described and claimed in the copending application of Ralph E. Ford, Serial No. 510,655, filed May 24, 1955. The door construction of this copending application is particularly advantageous because it affords access through the'complete closet opening without projecting a significant amount into the room off which the closet is disposed. The construction is particularly attractive to builders of new homes because of its low cost but it can also be adapted to old residences.

The present invention is directed to improvements in such door construction and an important object of the invention is to provide a folding door construction embodying means for deadening sound associated with the movement of such doors when made of metal, the said means also serving to reinforce and stiffen the individual panels.

Another object of the invention is to provide novel means for retaining the sound deadening means in the individual panels whereby to facilitate installation of the same.

Another object of the invention is to provide a folding door construction embodying improved guide means for guiding the sliding panels including means readily accessible for securing the guide means whereby the associated parts may be operatively related and the panels plumbed prior to final fastening.

Still another object is to provide an improved door pull whereby to facilitate manipulation of the door units.

Other objects and advantages will be apparent during the course of the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Figure 1 is a front elevation of the folding door construction embodying the present invention with the panels in closed position;

Fig. 2 is an enlarged exploded view of the folding door assembly, including the hardware;

Figs. 3 and 4 are enlarged vertical sections taken substantially along the lines 3-3 and 44, respectively, of Fig. l, with the panel in each View being broken;

Figs. 5 and 6 are enlarged horizontal sections taken substantially along the lines 5-5 and 66, respectively, of Fig. l; and

Fig. 7 is an elevational view of the sound deadening means employed in the folding door construction embodying the present invention.

The door construction generally comprises a pair' of door units which are pivotally secured at the leftand the right-hand sides of a closet opening or doorway. Each door unit comprises a pair of panels, an outside panel which is vertically pivoted adjacent one side of the closet opening, and an inside panel which is pivotally hinged to the outside panel. Each do'or unit functions to open and close one half of the closet opening in the manner disclosed in the copending application referred to. Guide means, including an upper or lower track, or both, serves as a pivot support for the outside panels and as a guide for the inside panels of the door-units in their opening and closing movement. Each of the panels when made of metal is provided with sound deadening means on the inside surfaces thereof, as will appear more fully hereinafter. Suitable hardware is provided for securing the assembly and an improved door pull is included to manipulate the door units.

Referring to the structure in more detail, only one door unit will be described as the two door units are identical except for being disposed on opposite hands of the closet or door opening. The closet or door opening comprises top and bottom horizontal surfaces generally designated 10, and vertical side surfaces generally designated 12. A leftand a right-hand door unit operate at opposite vertical side surfaces to completely close and fully open the door or closet opening. The left-hand door unit as viewed in Fig. 1 comprises an outside panel 9 and an inside panel 11. In the exploded view of Fig. 2 which depicts the door assembly from the inside of the doorway, the same panels 9 and 11 are shown. The outside panel 9 is adapted to be pivoted between the top and bottom horizontal surfaces 16 about a vertical axis adjacent one of the vertical side surfaces 12 of the door opening. The inside panel Ill is pivotally connected to and supported by the outside panel 9 as by hinges 14 so as to have a free end which slides across the door opening. In the closed position the panels 9 and 11 assume a coplanar position with the free end of the inside panel 11 extended to the center of the door opening and in the open posi tion panels 9 and 11 fold against one another outside of the door opening, the free end of the inside panel 11 having moved axially in the plane of the door opening toward the said vertical side surface to assume a position adjacent the pivot axis for the outside panel 9.

The panels are preferably formed from sheet metal although it will be understood that they may be formed from a number of other materials, examples being plywood, hardboard such as Masonite, and fiber glass-reinforced plastic. The vertical sides 13 of each panel extend outwardly from the central body portion 15 and have inturned back flanges 17 which terminate in reentrant lips 18. The vertical sides 13 together with the back flanges 17 stiffen the individual panels since they run the length thereof. Further stiffening is provided by transverse hat sections 19 disposed at the top and bottom of each of the individual panels the side flanges 20 of which are preferably spot welded along the lengths thereof to the body portion 15 as seen at 20'. The ends of each of the hat sections 19 are cut out but the webs thereof overlap and are spot welded at 19' to opposite back flanges 17 on each of the panels, it being noted that the door is constructed so that it can be readily fabricated by spot welding using production techniques. A substantially rectangular open cavity 21 is thus formed in each of the individual panels by the sections 19, the depth of each of the open cavities being defined by the distance between the inside surface of the back flanges 17 and the inside surface of the body portion 15 of the individual panels. Each of the open cavities 21 extends substantially the height of each individual panel between the upper and lower hat sections 19. The effective transverse perimeter of each of the open cavities 21 which is important for the purposes of the present invention as will appear hereinafter extends along the inside surface of the body portion 15 and outwardly from both sides thereof along the inside surface of opposite vertical sides 13 to the junction of the same with the inside surface of opposite back flanges 17. Stated differently, the effective transverse perimeter of each open cavity is defined by the distance between the inside surfaces of the back flanges on each panel measured along the body portion of each panel. It is preferable that the efiective transverse perimeter of each of the open cavities 21 be less than the width of the sound deadening means as will be hereinafter explained.

The sound deadening means is shown in detail in Fig. 7 and comprises a substantially rectangular board 27. The rectangular board 27 can be made of any number of suitable materials known to the art which have suflicient rigidity to remain in place and still be capable of being flexed. The board must possess a certain degree of antiacous'tical or aphonic properties, cardboard being a preferable class of materials. An example of a board suitable for the purposes of the present invention is a type C ISO-lb. test kraft flute corrugated board. The rectangular board 27 (as best shown in Fig. 7) has a pair of shallow notches 29 cut out from one vertical side and another pair of deeper notches 31 cut out from the other vertical side. The purpose of the notches is to facilitate bending of the board in the manner to be described and for a like reason are formed a plurality of longitudinally extending score lines a, b, c and d. The longitudinally extending score lines may be formed from equally spaced slits cut into the cardboard or from folds which may be permanently impressed into the board and the term score line is intended to include all such deformations which can be made to facilitate bending. The location of the score lines is important and as can be seen from Fig. 7 the single score line a extends longitudinally the length of the board along the line defined by the bottom of the shallow notches 29. The other three score lines b, c and d are located adjacent the opposite vertical side of the rectangular board. The score line b extends longitudinally the length of the board along the line defined by the bottom of the notches 31. Spaced from the score line b are the scorelines c and d and they extend longitudinally the length of the three solid portions remaining along the side from which the notches 31 are cut. The distance between the score lines b and c is shorter than the distance between the score lines c and d, which distance, in turn, is shorter than the distance between the score line d and the edge of the rectangular board 27.

The preferred manner of retention of the sound deadening means within each of the open cavities formed in the individual panels is frictional engagement with the inside 7 surfaces of the open cavities and transverse compression of the rectangular board by means on the "ertical edges of the panels. Fig. shows the final disposition of the corrugated board 27 relative to the individual panel 11. A preliminary position of a portion of the board is shown in outline with the score lines formed thereon being designated by prime reference numerals. The corrugated board is first folded vertically along the score lines a and b. The side of the corrugated board which has been folded along score line a is first inserted into the rectangular cavity 21 with the upturned portion between the score line a and the edge of the board abutting against the inside surface of one of the vertical sides 13 of the panel 11, the depth of notches 29 thus being the height of flanges 13. The opposite side of the board which has been folded along score line b is disposed at the other side of the rectangular cavity 21 with its upturned portion between the score line b and the edge of the board at this opposite side in the position shown in outline designated 27'. In this position, the width of the board is clearly illustrated as being greater than the effective transverse perimeter of the open cavity, as defined, and this is necessary in order that the board be placed under transverse com;

pression in its final position within the open cavity. The final position of the upturned portion between the score line b and the edge of the board is shown in full line section in Fig. 5 and into this position it is snapped by pressure applied in the vicinity of the score lines 0 and d which have been preliminarily flexed to facilitate snapping into final position. The edge of the board snaps under the re-entrant lip 18 as shown and in this position the upturned portion, between the score line b and the edge of the board, is arcuately flexed and placed under compression due to the confinement of this portion and its tendency to straighten. The reactive force developed by this portion against the inside surfaces of the back flange 17 and the vertical side 13 urges the entire board 27 against the inside surface of the opposite vertical side 13. The entire board 27 is thus placed under compression transversely of its length (or height since it is vertically disposed). The body of the board between the innermost score lines a and b bears flatly against the inside surface of the body portion 15 of the panel and the upturned portion between score line b and the edge of the board bears against the inside surface of the vertical side 13 with the said edge bearing against the inside surface of the back flange 17 so that the said upturned portion is arcuately flexed. The said edge may or may not, although preferably it does, bear against the inside surface of the re-entrant lip 18, but the latter, in any event, insures retention of the board within the cavity 21. The opposite upturned portion between score line a and, the opposite edge of the board bears against the inside surface of the opposite vertical side 13. The said opposite edge of the board preferably bears against the inside surface of the opposite back flange 17 as a reaction point from compression applied at the opposite side of the board. The board is thus restrained from movement within the cavity by frictional engagement with the inside surfaces of the cavity formed in the panel and by the transverse compression under which it is placed by virtue of its construction and arrangement with respect to the panel structure, no gluing or the like being required. It will be noted that in the final position of the board, while the upturned portion between score line b and the edge of the board is generally arcuately flexed, the greatest flexure is along the score line d and at the same time along the score lines b and c the board is nearly straight. The compressive forces transversely of the board are therefore significant as evident by the severe flexing along score line d, and are in fact the major factor contributing to the security with which the sound deadening means is retained within each panel.

.Each of the panels receives the same deadening means in'the manner described. In Fig. 5, the adjacent panel 9, shown in fragmentary section, contains an identical corrugated board disposed within its rectangular cavity in the opposite hand from the disposition of the corrugated board in panel 11 as it is immaterial as to which side of the panel the edge of the board containing the score line a is first inserted. With the sound deadening means installed in each of the individual panels, the noise associated with striking of the panels, or as they slide and fold in their opening and closing movements, is substanially reduced. The sound deadening means installed in the door construction as described gives body without weight to the doors such that their action is characteristic of more expensively constructed but heavier doors. The sound deadening means also serves to reinforce and strengthen somewhat the individual sheet metal panels so that the tendency to flex or buckle is considerably mini mized.

For manipulation of the door units there is shown in Fig. 6 an enlarged cross-sectional view of a door pull 32 which is molded from suitable plastic. The body portion of the door pull 32 is substantially rectangular in longitudinal cross-section (or vertical cross-section since the .door .pull is disposed with its length disposed vertically). The door pull is readily snapped into rectangular apertures 33 cut into the body portion of each of the outside panels and is recessed into the closet side of the door opening from the outside surface of the body portion 15 of the door panel. The door pull has molded integral thereon detent means in the form of an outwardly projecting annular ring 35 which cooperates with an outwardly projecting annular base 37 from which it is suitably spaced. The perimeter of the rectangular aperture 33 is embraced by the space between the annular ring 35 and the annular base 37 when the door pull is snapped into position. The annular ring 35 engages the inside surface and the annular base 37 engages the outside surface of the body portion 15 of the door panel so that the door pull is securely retained within the rectangular aperture 33. The body portion of the door pull is formed with parallel opposite vertical faces 39, 41 which are obliquely disposed with respect to the annular base 37, so that when the door pull is snapped into position, the body portion thereof is obliquely disposed with respect to the body portion 15 of the door panel. The vertical face 41 is shorter with respect to the annular base 37 than the vertical face 39 and, consequently, makes an acute angle with the body portion 15 of the door panel. The vertical face 41 is a distal face and the vertical face 39 is a proximal face with respect to the vertical side of the door opening (the direction of the location of'which is indicated by the arrow in Fig. 6) adjacent which the outside panel is pivotally hinged. Since the door pull is affixed to the outside panel and disposed near one vertical edge, a pull motion exerted on the door pull pivots the outside panel in a circular path about its opposite vertical edge adjacent the mentioned vertical side of the door opening. The acute angle between the distal vertical face 41 and the body portion 15 of the door panel provides leverage for a pull motion exerted thereon to open the door unit. Likewise, it provides leverage for a combined pull and push motion exerted on the same to close the door unit. Identical door pulls are afiixed to each of the outside door panels so that the vertical face of each door pull which makes an acute angle with the body portion of the panel is the distal face with respect to each of the vertical sides of the door opening. Manupulation of the door units is thus greatly facilitated.

The improved guide means embodying the present invention preferably comprises identical upper and lower tracks 43, but if a single track is employed, it is preferable that it be the upper track. The exploded view of Fig. 2 shows the construction and arrangement of the door units with respect to the upper and lower tracks 43, together with the necessary hardware Preferably, there is provided an anchoring member 45 through which the upper track is secured to the door arch. The lower track is secured in the floor across the closet or door opening. Associated with the upper and lower tracks 43 and with each of the outside panels, e. g., panel 9, are a pair of pivot pins 47 preferably constructed of nylon material and as described in the copending application referred to. Each of the pivot pins 47 is secured to L-shaped brackets 49, which in turn are adapted to be fastened to the outside panels in pairs, one at the top, and one at the bottorn by way of hat sections 19. The hat sections 19 have apertures as at 48 for threadably engaging screws as at 50 (Fig. 2) which extend through slots 52 in the L-shaped brackets 49 for securing the same to the hat sections. The slots provide for relative movement between the L-shaped brackets and the outside panels so that the dis ing 54 which is pressed into a suitable recess in each of the tracks 43. While the pivot pins 47 are free to rotate in their supports, they are prevented from moving axially along the tracks.

Also associated with the upper and lower tracks 43 but with each of the inside panels, is a pair of guide pins 51 secured to L-shaped brackets 53. The guide pins 51, as well as the brackets 53 to which they are secured, are also constructed and located as described in the above copending application (i. e., the axis of pins 51 is further from the uis of hinges 14 than is the axis of pins 47 so as to prevent binding or sticking in the tracks) and are similar to the pivot pins 47 and the brackets 49 previously described, but the manner in which they are disposed within the tracks and their function diiferentiate them from the pivot pins 47. The guide pins through their brackets are secured in pairs to the free end of each of the inside panels, one at the top and one at the bottom thereof. The guide pins are adapted to slide axially along in the tracks 43. Each pair of guide pins thus defines a vertical axis for the free end of each of the inside panels about which the inside panels pivot as they are being actuated to the open position. For each door unit, the location of the pair of guide pins on the inside panel with respect to the location of the pair of pivot pins on the outside panel must be such that the distance between the hinges or axis of hinging and the axis defined by the pair of pivot pins is smaller than the corresponding distance between the same axis of hinging and the axis defined by the pair of guide pins to permit the pair of panels to fold together and slide without binding, as set forth and described in detail in the aforementioned copending application. The sectional View of Fig. 4 through the free tance between each pair of pivot pins can be adjusted vertically. When the pivot pins 47 are thus secured to the outside panels, they are adapted to be disposed within the tracks 43, and each pair defines a vertical axis'about which each of the two outside panels pivot. Fig. 3 shows in greater detail the disposition within the upper and lower tracks 43 of the pivot pins 47 for outside panel 9. Each of the pivot pins 47 is rotatably supported in a bush:

end of the inside panel 11 shows in greater detail the disposition of the pair of guide pins 51 within the upper and lower tracks 43, and as can be seen from reference to this figure, the guide pins do not support the weight of the inside panel 11, the support for the latter panel being derived from outside panel 9. Each of the tracks 43, the cross-section of which is shown in Figs. 3 and 4, is generally arched-shaped and has a longitudinally extending channel 55 with vertical side Walls 56 depressed therein which is unsymmetrically located with respect to the transverse width of the track. A pair of step portions of unequal width, viz., a narrow step portion 57 and a wide step portion 59 extend from the vertical side walls 56 of the longitudinally extending channel 55 along the length thereof. With respect to the lower track, the narrow step portion 57 is disposed on the entrance side of the door opening so as to present a minimum of obstruction in the room in which the closet is located or from which the door opening is an exit. The wide step portion 59 is disposed on the closet or exit side of the door opening. The upper track is similarly disposed with the narrow step portion 57 on the entrance side of the door opening so that suitable trim as at 58 may be located as close as practicable to the door construction.

For afhxin the lower track to the floor and the upper track to the arch of the closet opening means is provided in the wide step portion 59 hidden from view within the closet proper. A plurality of apertures 61 are formed in the wide step portion 59 to receive securing means, e. g., screws which extend through the upper and lower tracks for affixing the same between the horizontal surfaces 10 of the closet or door opening.

Projecting laterally from each of the vertical side walls 56 into the longitudinally extending channel 55 in each of the tracks are rigid means in the form of inturned lip portions 63, 65 which are formed integral with each of the vertical sides 56 at the junction of the latter with each of the step portions 57, 59 respectively. The lip portions 63, 65 extend the length of each of the channels 55 and provide bearing surfaces that make substantially line contact with opposite sides of each of the guide pins 51 afiixed to the inside panels. As can be seen from Fig. 4,

7 the guide pins 51 project into the channels 55 out of contact with the side walls and are adapted to slide therein. Each door unit consisting of an outside panel and an inside panel is suspended in cantilever fashion on the pivot pins adjacent each vertical side of the closet opening. Thus, each door unit receives no support from the tracks except at the pair of pivot pins and, therefore, is free to slide between the same. When a single track is employed, it is still necessary to provide a pair of pivot pins and supports for each door unit. During movement of the inside panels, the lip portions 63, 65 make substantially line contact only with opposite sides of the guide pins so that a minimum of friction develops between the guide pins and the tracks within which they slide. Consequently, there is less frictional wear on the guide pins and smoother manipulation of the door units is achieved.

The manner of affixing the tracks within the closet opening by securing means which are accessible after all of the associated parts of the door construction are in operative relation assures proper installation of the door construction, as will be apparent from the following description of the proper method of installing the door units. The anchor member 45 is first securely afiixed to the arch of the closet opening, after which the upper track is aflixed to the anchor member 45. To the pair of hinged inside and outside panels are aflixed the pivot pins and guide pins by means of the L-shaped brackets. The lower track is laid on the floor and the outside panels are disposed so that the pivot pins affixed thereto engage the bushings in the tracks, and the inside panels are similarly disposed so that the guide pins are free to slide within the longitudinally extending channels in the tracks. The L-shaped brackets are adjusted to accommodate for the height of the particular closet opening. The door units are made plumb with the closet opening by shifting the lower track and following this, the lower track is fastened securely to the floor by the securing means in the wide step portion of the tracks. Final adjustments on the door units are made by raising or lowering the L-shaped brackets until the door units operate freely.

It will thus be seen that there has been provided by this invention a door construction in which the various objects hereinabove set forth, together with many practical advantages, are successfully achieved. While the preferred embodiment has been shown and described, it is to be understood that the invention is susceptible to variation, modification and change without departing from the spirit of the invention.

What is claimed is:

1. In a door construction for a doorway having top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal pancls each having a body portion of substantially the same height as the doorway, means on said panels for suspending same between said horizontal surfaces so that said panels are movable in the doorway toward one of said vertical side surfaces, each panel having means on the vertical edges of said body portion extending outwardly therefrom and having inturned back flanges to form an open cavity between said inturned back flanges and said body portion, and sound deadening means including a substantially rectangular flexible board having a width greater than the effective transverse perimeter of said cavity defined by the distance between the inside surfaces of said back flanges along said body portion, said board being disposed in said cavity with the body thereof contiguous with the inside surface of said body portion and with one vertical edge thereof contiguous with the inside surface of one of said back flanges, a vertical side of said board inward of the other vertical edge thereof being arcuately flexed behind a flange so that said board is retained against movement in said cavity by frictional engagement and transverse comp ession.

2. In a door construction for a doorway having top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal panels each having a body portion of substantially the same height as the doorway, means suspending one of said panels between said horizontal surfaces, means pivotally hinging the other of said panels to said one panel about a vertical axis so that said panels fold together from a coplanar relative position, vertical sides on each said body portion extending outwardly therefrom and having inturned back flanges to form an open cavity between said inturned backflanges and said body portion, and sound deadening means including a pair of substantially rectangular flexible boards each having longitudinally extending score lines formed adjacent one vertical side to facilitate bending thereof, the width of each said board being greater than the effective transverse perimeter of each said cavity defined by the distance between the inside surfaces of said back flanges on each said panel along each said body portion, each said board being disposed in each said cavity with the body thereof contiguous with the inside surface of each said body portion and with one vertical side of said board inward of one vertical edge thereof contiguous with the inside surface of one of said vertical sides on each said panel, the other side of each said board being arcuately flexed against the other of said vertical sides on each said panel so that each said board is retained against movement in each said cavity by frictional engagement and transverse compression.

3. In a door construction for a doorway having top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal panels each having a body portion of substantially the same height as the doorway and susceptible to oilcanning, each of said panels having means for suspending the same between said horizontal surfaces, means pivotally hinging said pair of panels together about a vertical axis so that said panels fold together from a coplanar relative position, vertical sides on each said body portion extending outwardly therefrom and having inturned back flanges to form an open cavity between said inturned back flanges and each said body portion, and means to prevent said oilcanning including a pair of substantially rectangular flexible boards each having notches cut out therefrom and longitudinally extending score lines formed on the vertical sides to facilitate bending thereof, the width of each said board being greater than the effective transverse perimeter of each said cavity defined by the distance between the inside surfaces of said back flanges on each said panel along each said body portion, each said board being disposed in each said cavity with the body thereof between the score lines contiguous with the inside surface of each said body portion and with one vertical side inward of one vertical edge thereof contiguous with the inside surface of one of said vertical sides on each said panel, the other side of each said board inward of the other vertical edge and outward of one of said score lines being arcuately flexed against 5 the other of said vertical sides on each said panel so that each said board is retained against movement in each said cavity by frictional engagement and transverse compression.

4. In a door construction for a doorway having top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal panels each having a body portion of substantially the same height as the said doorway, each said panel having means for suspending the same between said horizontal surfaces, means pivotally hing- 5 ing said pair of panels together about a vertical axis so a ing score lines formed on and notches cut out from the other vertical side of each said board to facilitate bending thereof, the width of each said board being greater than the effective transverse perimeter of each said cavity defined by the distance between the inside surfaces of said back flanges on each said panel along said body portion, each said board being disposed in each said cavity with the body thereof between the innermost score lines contiguous with the inside surface of each said body portion and with said one vertical side outward of said one score line contiguous with the inside surface of one of said vertical sides on each said panel, the said other vertical side of each said board outward of one of said plurality of score lines being arcuately flexed and having its vertical edge contiguous with the inside surface of one of said back flanges on each of said panels.

5. In a door construction having top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal panels each having a body portion of substantially the same height as the doorway, each said panel having means for suspending the same between said horizontal surfaces, means pivotally hinging said pair of panels together about a vertical axis so that said panels fold together from a coplanar relative position, vertical sides on each said body portion extending outwardly therefrom and having inturned back flanges to form an open cavity between said inturned back flanges and each said body portion, said inturned back flanges terminating in reentrant lips, and a pair of substantially rectangular flexible boards each having one longitudinally extending score line formed on one vertical side thereof and notches cut out from said one vertical side, a plurality of longitudinally extending score lines formed on and notches cut out from the other vertical side of each said board, said score lines and notches facilitating bending of said vertical sides, the width of each said board being greater than the effective transverse perimeter of each said cavity defined by the distance between the inside surfaces of said back flanges on each of said panels along each said body portion, each said board being disposed in each said cavity with the body thereof between the innermost score lines contiguous with the inside surface of each said body portion and with said one vertical side outward of said one score line contiguous with the inside surface of one of said vertical sides on each said panel, the said other vertical side of each said board outward of one of said plurality of score lines being arcuately flexed and having its vertical edge snapped under one of said re-entrant lips on each of said panels and contiguous with the inside surface of one of said back flanges on each of said panels.

6. In a door construction for a doorway having top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal panels each having a body portion of substantially the same height as the doorway, each said panel having means for suspending same between said horizontal surfaces, means pivotally hinging said pair of panels together about a vertical axis so that said panels fold together from a coplanar relative position, vertical sides on each said body portion extending outwardly therefrom and having inturned back flanges to form an open cavity between said inturned back flanges and each said body portion, and sound deadening means including a pair of substantially rectangular flexible boards forced into each said cavity cooperating with said vertical sides on each of said panels and being retained therein through frictional engagement and transverse compression.

7. In a door construction for a doorway having. top and bottom horizontal surfaces and vertical side surfaces, a pair of sheet metal panels each having a body portion of substantially the same height as the doorway, pivot means on one of said panels for vertically pivoting same between said horizontal surfaces, means hinging the other of said panels to the free end of said one panel so that said panels fold together toward one of said vertical surfaces from a coplanar relative position, vertical sides on each said body portion extending outwardly therefrom and having inturned back flanges to form an open cavity between said inturned back flanges and each said body portion, said inturned back flanges terminating in reentrant lips, and a pair of substantially rectangular flexible boards each having one longitudinally extending score line formed on one vertical side thereof and notches cut out from said one vertical side, a plurality of longitudinally extending score lines formed on and notches cut out from the other vertical side of each said board, the width of each said board being greater than the effective transverse perimeter of each said cavity defined by the distance between the inside surfaces of said back flanges on each said panel along each said body portion, each said board being disposed in each said cavity with the body thereof between the innermost score lines contiguous with the inside surface of each said body portion, said one vertical side of each said board outward of said one score line being contiguous with the inside surface of one of said vertical sides on each of said panels, the said other vertical side of each said board outward of one of said plurality of score lines being arcuately flexed and having its vertical edge snapped under one of said reentrant lips on each of said panels and contiguous with the inside surface of one of said back flanges on each of said panels so that said board is retained against movement in said cavity primarily by frictional engagement and transverse compression whereby the noise associated with the movement of said pair of panels is substantially reduced.

8. In a plural panel folding door construction, a pair of door panels hinged together so that they can be folded one against the other, each said panel being sounddeadened and comprising an elongated section of sheet metal forming said door panel, parallel flanges on each said panel extending substantially perpendicular to the surface of the panel, a sheet of cardboard engaging the surface of each of the panels between said flanges and acting as a sound-deadener, said cardboard having a flexible side edge parallel to said flanges which is bent back at an angle to the surface of the panel and held in bent position by engagement with one of said flanges, the other side edge of said cardboard engaging the other of said flanges, whereby the tendency of said bent edge to return toward said panel which is resisted by said flange acts to hold said cardboard against said panel and against said other flange.

9. In a plural panel folding door construction, a pair of door panels hinged together so that they can be folded one against the other, each said panel being sounddeadened and comprising a section of sheet metal forming said door panel and having a back surface, the sides of each said panel being turned back substantially perpendicular to said surface to form first and second flanges on opposite sides of said surface spaced apart by a first width, said second flange having an outer portion turned back toward the first flange and spaced rearwardly from said back surface, the end of said outer portion being turned back toward said back surface to provide a lip spaced from said second flange and from said back surface, said lip and outer portion defining a corner, a sheet of cardboard for each panel acting as a sounddeadener and having first and second side flanges spaced apart by a width slightly greater than said first width, said first and second side flanges cooperating respectively with the first and second panel flanges to hold the cardboard against said back surface, said cardboard being in engagement with said back surface with the second flange thereof in engagement with said second panel flange, the first flange of said cardboard being reversely bent and caught in said corner defined by said lip and outer portion.

10. The invention set forth in claim 9 wherein the distance between said lip and said first flange comprises a second width less than the first width, said cardboard having a score line formed thereon at the'base of said first flange to facilitate formationof said first fiange,'said cardboard having a second scorcline formed thereon at a distance spaced from said first score line by a distance substantially equally to said second width minus twice the thickness of said cardboard'whereby said cardboard may be bent along said second score line and insertedagainst said back surface between said lip and first flange, said cardboard having a third score line spaced from the outside of said first cardboard flange by a distance greater than said first width, the portion of said cardboard outwardly of said third score line forming said first flange.

11. The invention set forth in claim 10 including 12 notches cut out of the opposite edges of said cardboard to the depth of said first score line on one side and said second score line on the other side to facilitate bending of said cardboard along said score lines.

References Cited in the file of this patent UNITED STATES PATENTS 1,612,499 Etheredge Dec. 28, 1926 2,585,976 Teeter Feb. 19, 1952 2,616,122 Curtiss Nov. 4, 1952 2,717,664 Grafman Sept. 13, 1955 FOREIGN PATENTS 876,619 France Aug. 10, 1942 

